Modern telecommunications networks include mobile stations, such as cell phones, which utilize a SMARTCARD which includes a SIM (subscriber identity module). The SIM's have a memory chip that contains data such as the identity of the card holder (i.e., the service subscriber), billing information, and home location. When a cell phone user places a call, the SIM communicates the unique SIM code to the network. The network checks to see if the SIM code owner is a current subscriber to the network service, often by matching the SIM code with a list of authorized SIM codes. This authentication, or matching of SIM codes generally precedes all other network communication with the cell phone.
SMARTCARDs were developed to allow cell phone activities other than simple telephone calls. The SMARTCARD can contain microprocessors for, e.g., transaction management, data encryption and user authentication. The SMARTCARD or the SIM may include subscriber entered telephone numbers and other valuable information. Theft of the phone places this valuable information in the hands of others. In fact, the loss of the phone is probably less important than the loss of the valuable information contained therein. This is especially true for the new cell phones which now access the Internet, and for cell phones coupled with handheld computing devices, which browse the Internet, store Power Point presentations, and do rudimentary word processing, as well as scheduling appointments and maintaining expense accounts.
Many security features have been developed for cell phones. Most of these are related to prevention of theft of communication services by permanently disabling a stolen phone, temporarily disabling a phone for which the subscriber is in arrears, or blocking calls to geographical regions which are not part of the subscriber's contract.
U.S. Pat. No. 5,898,783 discloses a telecommunications network with disabling circuitry which can disable the SMARTCARD of the cell phone of a particular subscriber. The disable command can permanently incapacitate the SMARTCARD by destroying the power connection for the logic circuitry, or temporarily incapacitate the logic circuitry by erasing the memory within the card. According to this patent, the numbers of stolen phones can be reported to the network and entered into a database which is searched when any cell phone requests service, and a disable command or signal returned to the cell phone if its number is in the disable database. In the present invention, the subscriber erases the memory containing the private information without the additional steps and involvement of the network, giving the subscriber greater freedom and opportunity to safeguard their private information.
U.S. Pat. No. 5,734,978 describes a telecommunications system having a manufacturer preset destruct code stored in each cell phone. When a subscriber reports a phone stolen, the network's base station controller initiates a destruct program, using the destruct code. The destruct code destroys the data necessary for performing the telephone functions, but not the private data.
U.S. Pat. No. 6,259,908 describes a cellular phone system in which a locking code on a particular cell phone may be erased by means of a message transmitted through the cell phone system, but may not be erased or changed using the keyboard features of that phone. This arrangement has particular usefulness in a designated cellular system with many units, such as a communications network for the fire department of a large city. To set up or reconfigure the network, the entire network must be activated and the individual units (cell phones) assigned a particular number. According to the patent, all phones on the system have a locking code to prevent theft communications on the network until all units are assigned. This is a subscriber system approach to preventing theft of service of the communications system, and does not relate to the privacy of data of individual subscribers.